User Guide

28
Troubleshooting Your HRV System
Symptom Cause Solution
Poor airflows
 1/4 in (6 mm) mesh on outside hood is plugged
 Filters plugged
 Core obstructed
 House grills closed or blocked
 Dampers are closed if installed
 Poor power supply at site
 Ductwork is restricting HRV
 Improper speed control setting
 HRV airflow improperly balanced
 Clean exterior hoods or vents
 Remove and clean filter
 Remove and clean core
 Check and open grilles
 Open and adjust dampers
 Have electrician check supply voltage
 Check duct installation
 Increase the speed of the HRV
 Have contractor balance HRV
Supply air feels cold
 Poor location of supply grilles, the airflow may irritate the
occupant
 Outdoor temperature extremely cold
 Locate the grilles high on the walls or under the base-
boards, install ceiling mounted diffuse or grilles so as
not to directly spill the supply air on the occupant (i.e.
over a sofa)
 Turn down the HRV supply speed. A small duct heater
(1 kW) could be used to temper the supply air.
 Placement of furniture or closed doors is restricting the
movement of air in the home
 If supply air is ducted into furnace return, the furnace
fan may need to run continuously to distribute ventila-
tion air comfortably
Dehumidistat in not
operating
 Outdoor temperature is above 15°C (59°F)
 Improper low voltage connection
 External low voltage is shortened out by a staple or nail
 Check Dehumidistat setting it may be on OFF
 Dehumidistat is functioning normally (see Auto Dehu-
midistat Disable in this manual)
 Check that the correct terminals have been used
 Check external wiring for a short
 Set the Dehumidistat at the desired setting
Humidity levels are
too high condensa-
tion is appearing on
the windows
 Dehumidistat is set too high
 HRV is not sized to handle a hot tub, indoor pool etc.
 Lifestyle of the occupants
 Moisture coming into the home from an unvented or unheat-
ed crawl space
 Moisture is remaining in the wash room and kitchen areas
 Condensation seems to form in the spring and fall
 HRV is set at too low a speed
 Set Dehumidistat lower
 Cover pools, hot tubs when they are not in use
 Avoid hanging clothes to dry, storing wood and venting
clothes dryer inside. Firewood may have to be moved
outside
 Vent crawl space and place a vapor barrier on the floor
of the crawl space
 Ducts from the washroom should be sized to remove
moist air as effectively as possible, use of a bathroom
fan for short periods will remove additional moisture
 On humid days, as the seasons change, some condensa-
tion may appear but the homes air quality will remain
high with some HRV use
 Increase speed of the HRV
Humidity levels are
too low
 Dehumidistat control set too low
 Blower speed of HRV is too high
 Lifestyle of occupants
 HRV airflows may be improperly balanced
 Set Dehumidistat higher
 Decrease HRV blower speed
 Humidity may have to be added through the use of
humidifiers
 Have contractor balance HRV airflows
HRV and/or ducts
frosting up
 HRV airflows are improperly balanced
 Malfunction of the HRV defrost system
 Note: minimal frost build-up is expected on cores before
unit initiates defrost cycle functions
 Have HVAC contractor balance the HRV
Condensation or ice
build up in insulated
duct to the outside
 Incomplete vapor barrier around insulated duct
 A hole or tear in outer duct covering
 Tape and seal all joints
 Tape any holes or tears made in the outer duct cover-
ing, ensure that the vapor barrier is completely sealed
Excess water in the
bottom of the HRV
 Drain pans plugged
 Improper connection of HRV’s drain lines
 HRV is not level
 Drain lines are obstructed
 HRV heat exchange core is not properly installed
 Look for obstructions in the drain line
 Look for kinks in the drain line
Excessive vibration
 Dirt on fan wheels  Have contractor service HRV